ATSAMB11XR datasheet(43/87 Pages) MICROCHIP

43 / 87 page

fPWM

base can be selected to have different values according to Table 9-6. The minimum and maximum

frequencies supported for each clock selection are also listed in the table.

Table 9-6. fPWM Range for Different fPWM Base Frequencies

fPWM

base

fPWM max.

fPWM min.

26 MHz

406.25 kHz

1.586 kHz

13 MHz

203.125 kHz

793.25 Hz

6.5 MHz

101.562 kHz

396.72 Hz

3.25 MHz

50.781 kHz

198.36 Hz

9.8

Clock Output

The ATSAMB11-XR2100A and ATSAMB11-ZR210CA have an option to output a clock. The clock can be

output to any GPIO pin via the test MUX. Note that this feature requires that the ARM and BLE power

domains stay on. If BLE is not used, the clocks to the BLE core are gated off, resulting in small leakage.

The following two methods can be used to output a clock.

Note: Refer the BluSDK Smart BLE API Software Development Guide for details on how to enable the

32.768 kHz clock output.

9.8.1

Variable Frequency Clock Output Using Fractional Divider

The ATSAMB11-XR2100A and ATSAMB11-ZR210CA can output the variable frequency ADC clock using

a fractional divider of the 26 MHz oscillator. This clock needs to be enabled using bit 10 of the

lpmcu_clock_enables_1 register. The clock frequency can be controlled by the divider ratio using the

sens_adc_clk_ctrl register (12-bits integer part, 8-bit fractional part).The division ratio can vary from 2 to

4096 delivering output frequency between 6.35 kHz to 13 MHz. This is a digital divider with pulse

swallowing implementation, so the clock edges may not be at exact intervals for the fractional ratios.

However, it is exact for integer division ratios.

9.8.2

Fixed Frequency Clock Output

The ATSAMB11-XR2100A and ATSAMB11-ZR210CA can output the following fixed-frequency clocks:

•

52 MHz derived from XO

•

26 MHz derived from XO

•

32.768 kHz derived from the RTC XO

•

26 MHz derived from 26 MHz RC Osc.

•

6.5 MHz derived from XO

•

3.25 MHz derived from 26 MHz RC Osc.

For clocks with frequency of 26 MHz and above, ensure that external pad load on the board is minimized

to get a clean waveform.

9.9

Three-axis Quadrature Decoder

The ATSAMB11-XR2100A and ATSAMB11-ZR210CA have a three-axis Quadrature decoder (X, Y, and Z)

that can determine the direction and speed of movement on three axes, requiring in total six GPIO pins to

interface with the sensors. The sensors are expected to provide pulse trains as inputs to the quadrature

decoder.

ATSAMB11XR/ZR

Datasheet Preliminary

DS70005342A-page 43

ATSAMB11XR датащи(PDF) 43 Page - Microchip Technology

ATSAMB11XR датащи(HTML) 43 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87

датащи скачать

ссылки URL